One of the themes addressed in the novel is social media's power to bring people together. Maddy and Olly get to know each other by means of text messaging—something that is a matter of course in today's society, but which has special import for this isolated couple.

A related theme is the trope of star-crossed lovers whose love is thwarted by circumstances. Maddy and Olly have unnatural barriers to their burgeoning teenage relationship and must both mature to a unique extent and overcome exceptional obstacles to be together as a couple.

A final theme is intimacy. The novel is told in the form of Maddy's diary, which affords the reader a strong perceived connection with this isolated young protagonist. Additionally, because Maddy has so few acquaintances, it is suggested that those with whom she is acquainted are especially close and precious.